slowparse doesn't support IE8

[toolness]

I tried hacking on a throwaway branch to see if it could work, and aside from obvious things like fixing Array.forEach() and String.trim(), the big problem was that text and attribute nodes don't seem to support expando properties in IE8. If we want to support IE8, we'll have to push all the parseInfo data for text and attributes up into their parent elements' parseInfo structure.

[toolness]

That said, slowparse does work on IE9 without any problems.